This invention relates to gas turbine engines, and more particularly, to swirler arrangements for supplying combustion air to the combustor of gas turbine engines.
Gas turbine engines include a combustor structure wherein fuel is burned to supply the necessary energy. To effect combustion fuel is supplied to a combustion zone and air is supplied in a manner to effect optimum mixing of the air and fuel for effective combustion. Usually the fuel is supplied through a fuel nozzle positioned at one end of the combustion zone and air is supplied through a surrounding swirler which imparts a swirling motion to the air so as to cause the air to be mixed thoroughly with the fuel.
In one conventional structure the swirler is provided with a plurality of angularly-directed passages which cause a swirling of the air within the combustion zone and thereby thorough mixing with the fuel. In this conventional structure the swirler is mounted on the fuel nozzle and includes a portion disposed in sliding engagement with a portion of the wall of the combustion zone. The air through the angularly-directed passages of the swirler tends to cause the swirler to rotate about its mounting on the fuel nozzle. In order that the swirler be enabled to provide the necessary swirling of the air and the effective mixing of the air and fuel, it is necessary that the rotation of the swirler be limited. In one conventional structure this is accomplished by providing a tab on the swirler and a stop on the combustor structure, the stop limiting the rotation of the swirler.
However, the combustor structure is vibrationally active and moreover there is substantial thermal expansion of components during operation of a gas turbine engine. As a result there is relative movement between the tab and the stop resulting in significant wear which eventually requires repair and increases maintenance costs.
By the present invention this problem of the prior art has been overcome and an arrangement for limiting the rotational movement of the swirlers has been provided in which the aforementioned wear is minimized.
It is an object of this invention to provide a combustor structure for a gas turbine engine including swirlers associated with fuel nozzles and including a stop arrangement for limiting rotation of the swirlers in a manner which minimizes wear and thereby reduces maintenance.